Owing to its reliability and performances, the joint according to the invention is particularly adapted so as be able to be used in spatial applications and in particular in the production of the solar panels of satellites formed of various elements joined together and whose deployment occurs in space. However, a large number of applications are possible, both in space and on Earth. As regards the first category, one could mention mobile flaps, manipulator arms, etc., as simple examples. As regards land applications, such examples include uses in robotics and, for example, in the nuclear, food, pharmaceutical and chemical industries.
Currently, the various elements constituting articulated solar panels are usually interconnected by hinge-type joints characterized by rubbings occuring i.e., friction induced, between the parts in contact and moving in relation to each other. Such joints need to be lubricated, this proving to be extremely difficult to obtain having regard to the extreme temperature and vacuum conditions to which the satellite is subjected at the time the latter is launched and once it is placed in orbit in space. In these conditions, the materials have a tendency to naturally weld together or get stuck together, which risks resulting in the non-deployment of the panel.
In addition, current joints usually ensure deployment of panels by means of motorization or propulsion including, for example, torsional springs. The extensive and scattered rubbings or friction of these joints requires the need to have sufficient strength of propulsion so as to obtain an adequate propulsion margin. Should friction be insignificant, the end of deployment impacts may therefore be considerable. In order to limit these impacts, which would result in a significant structural impact, a speed adjustment system is added to these current joints. Moreover, any extensive scattered friction thus means that deployment geometry cannot be accurately predicted, it then being necessary to synchronize deployment of the various elements constituting the panels, as illustrated in particular by the document FR-A-2 371 343.
The document U.S. Pat. No. 3,386,128 considers the case of connecting two articulated elements by means of several spring rods with an arc of a circle section, said rods being secured to the two faces opposite these elements. Thus, an antifriction joint is embodied, said joint applying between the elements a drive torque tending to automatically deploy said elements and exerting a locking pressure between the latter when in the deployed position.
However, this joint does not provide any relative guidance between the elements when deployed, so that stray movements, such as torsional or oscillation movements, may occur when, for example, the satellite is launched, when the panel is deployed or under the effect of any thermal gradients to which the satellite is subjected. Such movements are not acceptable in practice, as they may possibly damage the panels themselves or other parts of the satellite.
Furthermore, the spring rods described in the document U.S. Pat. No. 3,386,128 have of necessity a limited thickness so as to guarantee good elasticity during all the deployment phase. Thus, to obtain a high drive torque with satisfactory locking pressure requires that a large number of plates be provided, which results in exaggeratedly increasing the spatial requirement of the joint.
Secondly, the document FR-A-2 122 087 refers to a hinge in which the two adjacent articulated elements are in contact with each other via convex cylindrical surfaces. These two elements are connected by at least two flexible strips whose extremities are secured to each of the elements, so that the strips cross between the cylindrical surfaces.
Such a hinge, which is also an antifriction hinge, does not comprise any propulsion or locking device in the opening position. Furthermore, it is not suitable for the aforesaid applications, as the thermal gradients to which it would then be subjected would inevitably lead to the appearance of play between the elements, resulting in undesirable torsional effects between the panels owing in particular to the stresses borne at the time the satellite is launched and at the end of deploying the articulated elements.